Method to harrow by tines and weeding harrow

Abstract

When removing weeds by harrowing with a harrowing implement (1) that has harrow tines (5) pivoting against spring force, the force with which the harrow tines (5) act in the area of ​​cultivated plants is selected to be lower than the force with which the harrow tines (5) act in the area of ​​weeds. In the harrowing implement (1), pneumatic springs assigned to the harrow tines (5) acting in the area of ​​cultivated plants are subjected to a lower pressure by compressed air than pneumatic springs assigned to the harrow tines (5) acting in the area of ​​weeds.

Description

[0001] The invention relates to a method for removing weeds by harrowing and a harrowing device having the features of the introductory parts of the independent claims.

[0002] Harrows (short "harrows") are known, for example, from EP 3 738 419 A1.

[0003] The familiar harrow features several harrow tines pivoted in a support frame. The harrow tines are pre-tensioned into their operating position by pneumatic cylinders acting as springs. When using the familiar harrow to remove weeds, the harrow tines pivot more or less depending on the soil conditions. The force exerted by the harrow tines is so great that only weeds are pulled out, while cultivated plants remain standing.

[0004] In the harrow known from EP 3 738 419 A1, this is achieved by supplying compressed air to the pneumatic cylinders via pressure control valves. Due to the pressure control valves, the pressure in the pneumatic cylinders and the force exerted by the tines (tine pressure) are the same in all pivoting positions of the harrow tines.

[0005] When harrowing with the help of the well-known harrow device, the aim is for the harrow tines to only pull out weeds, while leaving cultivated plants standing.

[0006] This is not always easily possible because lateral movements occur when harrowing with the known harrowing device, meaning that the harrow tines can also damage crops, for example, by tearing them out, and because all harrow tines act with the same force ("tine pressure"). WO 2020 / 173752 A1 (= US 11,423,662 B2) relates to a device for removing or destroying weeds, comprising a first image recording device for recording a first soil image, a data processing unit connected thereto, and an agricultural device controlled by the data processing unit, which is designed for the selective removal or destruction of weeds.The data processing unit is designed to receive the first soil image from the first image recording device, to receive manually determined position data from at least one connected terminal, which identify the position of weeds and / or cultivated plants and / or soil structures, for example rows of plants, identified in the first soil image by one or more users, and to control the agricultural device on the basis of the position data in such a way that it selectively removes or destroys weeds.

[0007] The invention is based on the object of developing the known method and the known harrowing device mentioned at the outset in such a way that cultivated plants are protected during harrowing.

[0008] This is achieved, on the one hand, by the features of the independent claim directed to the method and, on the other hand, by the features of the independent claim directed to the harrowing device.

[0009] Preferred and advantageous embodiments of the invention are the subject of the subclaims.

[0010] Since the invention adjusts the tine pressure in such a way that harrow tines that only hit weeds in order to pull them out act with higher tine pressure, whereas harrow tines in the area of ​​cultivated plants act with lower tine pressure, cultivated plants are protected.

[0011] This ensures that weeds are effectively removed (greater tine pressure), but crops are protected (lesser tine pressure).

[0012] This can be achieved by adjusting the pressure control valves assigned to the pneumatic cylinders that act as springs so that the harrow tines that work between crops operate with lower tine pressure. In contrast, the pressure control valves assigned to the pneumatic cylinders that act as springs are adjusted so that the pressure in the pneumatic cylinders is lower. In contrast, the pressure control valves assigned to the pneumatic cylinders that act between crops to pull out weeds are adjusted so that the pressure in the pneumatic cylinders is higher, resulting in greater tine pressure.

[0013] In a further development of the invention, it can be provided that at least one camera is provided which detects in which area of ​​the harrow device there are cultivated plants, so that on the basis of the images thus detected, the pressure control valves are adjusted so that harrow tines acting in the area of ​​cultivated plants work with a lower tine pressure.

[0014] The basic idea of ​​the present invention is that the harrow tines, as spring-loaded pneumatic cylinders of each individual harrow tine of the harrow device, are selectively subjected to one of at least two different pressures, and thus the harrow tines act on the soil with different forces.

[0015] When harrowing, the goal is to harrow as early as possible. This allows for lower tine pressure to be applied in a row of crops—within a predefined range—to prevent the crops from being pulled out. In contrast, greater tine pressure is applied between crop rows to ensure effective weed control.

[0016] To control the harrow and set the tine pressure to the desired value - lower tine pressure in the area of ​​cultivated plants, higher tine pressure in the area of ​​weeds - a bandwidth (= area around the cultivated plants in which lower tine pressure is used) can be entered into the harrow.

[0017] This can be done by creating tracks, for example using GPS, when cultivating the crops, which are then used when harrowing to define the area of ​​the crops in which less tine pressure is applied.

[0018] Alternatively, and possibly additionally, it is possible to record rows of crops using a camera and thus define areas that are subject to less tine pressure.

[0019] Further details and features of the invention will become apparent from the following description of exemplary embodiments with reference to the drawings. It shows: Fig. 1 shows a top view of a first embodiment of a harrow in a field of cultivated plants, Fig. 2 shows a second embodiment of a harrow in a field of cultivated plants, Fig. 3 shows a side view of three harrow tines with their holder, and Fig. 4 shows a pneumatic diagram of the harrow according to the invention.

[0020] A harrow device 1 according to the invention (device for harrowing, "harrow") comprises a support frame 2, which in the illustrated embodiment has several bars 3. The bars 3 are connected to one another via cheeks 4 arranged in the support frame 2. The bars 3 are rotatably mounted in bearings within the cheeks 4, so that the bars 3 can be rotated about axes parallel to their longitudinal extensions.

[0021] To rotate the bars 3, arms are attached to them, which are connected to each other via coupling rods. The connections between the free ends of the arms and the coupling rods are designed as joints, so that the bars 3 can be rotated by adjusting the coupling rods with the aid of a hydraulic cylinder. In this way, harrow tines 5 attached to the bars 3 can be rotated from a downward-facing position (= working position, Fig. 3 ) can be swivelled upwards into a ready position (= transport position).

[0022] The harrow tines 5 made of spring steel have angled, free ends 6, whereby the angled ends 6 engage in the soil 7 in order to remove weeds by pulling them out (cf. Fig. 3 ).

[0023] The harrow tines 5 are attached to levers 8. The levers 8 are pivotally mounted in supports 9 in pivot bearings 12. The supports 9 are attached to the beams 3 of the support frame 2. A pneumatic cylinder 10, which acts as a pneumatic spring, is pivotally supported on each support 9. The piston rod 11 of the pneumatic cylinder 10 is pivotally connected to the lever 8, which supports the harrow tines 5. The point at which the piston rod 11 of the pneumatic cylinder 10 is connected to the lever 8 is spaced from the pivot bearing 12 of the lever 8.

[0024] By applying pressure to the pneumatic cylinders 10, these act as a spring and the harrow tines 5 are pre-tensioned into their active position, which is defined, for example, by a stop.

[0025] The pneumatic cylinders 10 are supplied with compressed air via pressure control valves 20. This makes it possible to keep the tine pressure, i.e. the force with which the free ends 6 of the harrow tines 5 act on the soil 7, constant in all pivoting positions of the harrow tines 5.

[0026] The harrow tines 5 can pivot when working uneven soils. The pressure control valves 20 ensure that the harrow tines 5 act on the soil with the same force (= the same tine pressure) in all pivot positions of the harrow tines 5. This prevents the harrow tines 5 from acting on the soil with greater tine pressure in the area of ​​raised soil bumps and with lesser tine pressure in the area of ​​depressions (hollows). Such depressions in the soil can be, for example, tractor tracks. Elevations can be, for example, ridges around potato plants.

[0027] At the Fig. 1 In the embodiment shown, the tine pressure of harrow tines 5 located in rows of crops is adjusted based on previously stored tracks recorded using GPS coordinates during the cultivation of the crops. By entering the distance (b) between two rows of crops and a belt width (a), the area in which lower tine pressure is applied to protect the crops is determined.

[0028] Since the distance (b) between rows of crops and the belt width (a) are known, an area is created between the rows of crops in which increased tine pressure can be applied to effectively remove (pull out) weeds.

[0029] If - as in the Fig. 1 In the embodiment shown, a camera 15 and downstream image processing software are installed in the harrow 1, and crops are detected. This allows increased tine pressure to be applied in the areas between the rows of crops, so that the harrow tines effectively remove weeds between the rows of crops.

[0030] At the Fig. 2 In the embodiment shown, two cameras 15 and 16 are provided, namely one camera 15 on the harrow 1 and a second camera 16 on the front of the tractor 17. In this embodiment, it is possible, for example, to work in such a way that a circular area 18, for example, is defined around individual crop plants detected by the cameras 15 and 16, in which area the harrow tines 5 work with lower tine pressure in order to protect the crop plants. Outside of the thus defined (circular) area 18, it is possible to work with increased tine pressure. More than two cameras 15 can also be arranged on the harrow 1 according to the invention in order to cover a larger area. With several cameras 15 on the harrow, it is possible - especially in the case of the Fig. 2 shown embodiment - it is possible to react to each individual crop by adjusting the tine pressure accordingly using the pressure control valves 20. The number of cameras 15 mounted on the harrow 1 can be selected, in particular, taking into account the width of the harrow device 1.

[0031] In Fig. 3 It is schematically indicated that the pneumatic cylinders 10 of harrow tines 5 acting between crop rows are subjected to increased air pressure P1 (higher tine pressure). In contrast, the pneumatic cylinders 10 of harrow tines 5 in the area of ​​crops are subjected to lower air pressure P2 (lower tine pressure) in order to protect the crops.

[0032] The Fig. 4The pneumatic diagram of the harrow 1 according to the invention shown comprises a compressed air source 21, a water separator 22, a pressure setting 23 and a pressure gauge 24. The compressed air source 21 can, for example, be a compressed air generator (e.g. a compressor) provided on the tractor 17.

[0033] Two proportional pressure control valves 20 ("proportional valves") are provided in connection with the compressed air generator 21, which are set to different air pressures P1 and P2.

[0034] In front of the pneumatic cylinders 10, which load the harrow tines 5 as pneumatic springs, solenoid valves 25 are provided, which connect the pneumatic cylinders 10 either to the compressed air line 26, in which the higher air pressure P1 prevails, or to the compressed air line 27, in which the lower air pressure P2 prevails.

[0035] It is thus possible to apply compressed air to the harrow tines 5 and the pneumatic cylinders 10 assigned to them with a pressure that corresponds to the desired tine pressure - lower tine pressure in the area of ​​cultivated plants, higher tine pressure in the area of ​​weeds, i.e. in the area outside of cultivated plants.

[0036] Within the scope of the invention, it is also possible to connect a proportional valve as a pressure control valve 20 upstream of each pneumatic cylinder 10 serving as a spring, so that for each harrow tine 5, independently of the other harrow tines 5, the desired tine pressure can be selected by selecting the corresponding pressure of the compressed air supplied to the pneumatic cylinder 10.

[0037] In summary, an embodiment of the invention can be described as follows: When removing weeds by harrowing with the aid of a harrowing device 1 having harrow tines 5 that can pivot against spring force, the force with which the harrow tines 5 act in the area of ​​cultivated plants is selected to be smaller than the force with which the harrow tines 5 act in the area of ​​weeds. In the harrowing device 1, pneumatic springs assigned to harrow tines 5 acting in the area of ​​cultivated plants are subjected to a lower pressure by compressed air than pneumatic springs assigned to harrow tines 5 acting in the area of ​​weeds.

Claims

1. A method for removing weeds by harrowing with the aid of a harrowing device (1) having harrow tines (5) which can be pivoted against spring force, the free ends (11) of the harrow tines (5) acting with an adjustable force, characterized in that the force with which the harrow tines (5) act in the area of ​​cultivated plants is smaller than the force with which the harrow tines (5) act in the area of ​​weeds.

2. Method according to claim 1, characterized in that the area, in particular rows of crops, in which harrow tines (5) act with less force is recorded by GPS coordinates that were stored during cultivation of the crops.

3. Method according to claim 1, characterized in that the area, in particular the rows of cultivated plants, in which harrow tines (5) act with less force, is recorded by at least one camera.

4. Method according to claim 3, characterized in thata camera (15) which, with respect to the working direction, is arranged in front of the harrow (1) and a further camera (16) which is arranged on a tractor (17) arranged in front of the harrow (1) are used.

5. Method according to one of claims 1 to 4, characterized in that Crops are individually recorded and that an area (a, 18) is selected next to recorded crops in which the force with which the harrow tines (5) act is smaller than outside the selected area.

6. Harrow device (1) for carrying out the method according to one of claims 1 to 5, comprising harrow tines (5) which can be pivoted against spring force, the springs being pneumatic springs which are supplied with compressed air via pressure control valves (20), characterized in thatpneumatic springs which are assigned to harrow tines (5) acting in the area of ​​cultivated plants are subjected to a lower pressure by compressed air than pneumatic springs which are assigned to harrow tines (5) acting in the area of ​​weeds.

7. Harrow according to claim 6, characterized in that Pressure control valves (20) are controlled by a controller based on GPS coordinates generated during the cultivation of crops.

8. Harrow according to claim 6, characterized in that at least one camera (15) is provided on it for detecting cultivated plants.

9. Harrow according to claim 8, characterized in that , with respect to the working direction, at least one camera (15) is arranged on the front of the harrow (1) and a further camera (16) is arranged on a tractor (17) for the harrow (1).

10. Harrow according to one of claims 6 to 9, characterized in thata compressed air source (21) is provided, that at least two pressure control valves (20) which are set to different pressures (P1 and P2) are connected to the compressed air source (21), and that valves, in particular solenoid valves (25), are provided for connecting the pneumatic springs selectively to one or the other pressure control valve (20).

11. Harrow according to claim 10, characterized in that the compressed air source (21) is a compressed air generator provided on a towing vehicle, in particular a compressor.

12. Harrow according to one of claims 6 to 11, characterized in that a pressure control valve (20) is connected upstream of each pneumatic spring.

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